NASA and DARPA working towards quiet supersonic planes with XPlanes

The return of supersonic passenger travel is one step closer to reality with NASA’s award of a contract for the preliminary design of a low boom flight demonstrator aircraft. This is the first in a series of X-planes in NASA’s New Aviation Horizons initiative, introduced in the agency’s Fiscal Year 2017 budget. NASA said if funding comes through, the new planes could grace the skies as early as 2020.

NASA selected a team led by Lockheed Martin to complete a preliminary design for the QueSST X-plane. This endeavor supports NASA’s Commercial Supersonic Technology Project, which aims to better understand acceptable commercial supersonic aircraft sound levels across the country and develop a way for piloted aircraft to fly fast with low boom.

QueSST is designed to fly at Mach 1.4, 55,000 feet above the ground. The aircraft is shaped to separate the shocks and expansions associated with supersonic flight to reduce the volume of the shaped signature. QueSST’s “heartbeat” will be dramatically quieter than the traditional “N-wave” sonic boom associated with the current supersonic aircraft in flight today. The Skunk Works team has been advancing this technology for the last 20 years as part of multiple efforts.

The demonstrator, at 90 feet long, will be smaller than future civil supersonic aircraft. The goal is to eventually have commercial supersonic transportation. The Concorde’s sound at cruising altitude was about 105 decibels, but Buonanno said that based on tests, the X-plane would generate 70 to 80 decibels of noise. Quick and quiet are the buzz words.

NASA’s plan regarding the X-plane is extremely ambitious, setting out to develop a whole series of new X-planes over the next 10 years. One of the planes will be roughly the size of a business jet that burns low-carbon bio-fuels and generates such quiet sonic booms that people on the ground will barely hear them

Meanwhile, DARPA is working on a design of their own for an X-plane with a stacked wing frame that has a series of rotors mounted in between. The rear-mounted wing would create a vertical thrust for takeoff and landing, then rotate to provide horizontal thrust for cruise and second, smaller wing near the nose of the plane would work the same way. DARPA says its X-plane would fly as fast as 460 mph and could be in the air by as early as 2018.

Other planes that are now in development include the four-seat Tecnam twin replacing the wing and engines with a series of electric-powered propellers which aims to produce an emissions-free flight.

Another hybrid design that looks like a flying fish could be the airliner of the future, with turbofan engines in the back shielded by two vertical tails to protect people on the ground from engine noise.